N-alkyl-.alpha.-dialkylaminoacetohydroxamic acid derivatives are highly selective reagents that are useful for the deacylation of esters in an organic solvent under a substantially neutral condition [Journal of Synthetic Organic Chemistry, Japan (Yuki Goseikagaku Kyokai Shi), Vol. 47, 795 (1989); Tetrahedron Lett., 30, 207 (1989); JP-A-63-316755 (the term "JP-A" as used herein means an unexamined published Japanese patent application); JP-B-6-99382 (the term "JP-B" as used herein means an examined Japanese patent publication), JP-A-63-316743]. In JP-B-6-99382, as a typical example, a method for producing an N-methyl-.alpha.-dimethylaminoacetohydroxamic acid is described, and the specification thereof discloses a method for reacting N,N-dimethylglycine methyl ester with N-methylhydroxylamine hydrochloride, in the presence of sodium hydroxide, in a mixed solvent consisting of water and methanol.
It is difficult to say that such a conventional method is satisfactory, because the reaction time at room temperature according to the conventional method is as long as 7 days, which results in increased production cost. Further, our investigation made clear that hydrolysis of N,N-dimethylglycine methyl ester, as a raw material, occurs as a side reaction under the above-described reaction conditions, and consequently it causes a problem. That is, the conventional method necessitates a particular operation in order to remove N,N-dimethyl glycine as a by-product, and the same is not advantageous to a practical method in consideration of a processing amount, the number of persons required, the time required, and reduction in a yield of the objective compound. As a result, the development of an efficient and advantageous production method that causes no side-reaction has been desired.